I was wondering this question,I could not Find anything by Search,and went through 10 pages of "nothing".
.I Haven't seen an S5 AFM up close,but are they not Cone Type?.and the S4 AFM,as I know all too well is a Flapper type.
It got me thinking,Can the Cone type S5 AFM be wired into the S4 Harness and used?This Question is in Reference to Eliminating the Flapper Type AFM.( I sort of Hate them,But What the Heck,If I have to use it,I guess I can live with it!)
.Wiring Gurus,or anyone?.Please.Thanks .
Happy Holidays.STYX.

 

I'm 95% sure you can't very easily, I imagine you would have to switch to an S5 harness and ECU.

the easiest way to get ride of the flapper type is to get a stand alone with a map sensor. then you don't have to have an AFM at all

also, if you do find a way to do this, go with a 929 AFM (I think it's a 929), it's a little bigger than the S5 one, but the same general concept. search for it, there is a write up about it somewhere.

 

If you're really good, you can swap out the afm for a hot wire maf.

http://howto.globalvicinity.com/gv_w...=120&co=1&vi=1

 

https://www.rx7club.com/showthread.p...t=S5+to+S4+afm

I've never done it. Just seen the opinions about it on this site. I doubt I'll ever do it because none of my cars/engines can overcome the stock S4 vane type afm, plus there's less area on a series five afm anyway.

There's a number of threads on this. You have to look a seperate the chaff from the wheat. Advanced search using NZCONVERTIBLE and the words S5 to S4 AFM for the search words.

 

too bad it doesnt tell us anything about how to do it.

 

I know people claim the S4 afm is better due to area but the S5 afm physically flows more air.

I wish he'd have done a writeup. I don't have a fatory ecu anymore but I think having this as a mod would be very beneficial to the community as the afm is a restriction that costs about 10% in power. I've also seen people say that the afm can't be a restriction because at full throttle the plate doesn't open all the way. Due to the way the afm is shaped and the way air works against the plate, it can't open all the way. It can still be a restriction though. The S5 afm is cone shaped and flows air more smoothly which helps it flow more.

 

Yes, but you would need to figure out how to compensate for the different vane resistance ranges between the two series, as well as figure out a safe way to fix the engine kill switch issue. See the AFM diagrams in the factory service manuals. FYI it is my opinion that this conversion is a complete waste of time, but knock yourself out if you wish.

Even with the higher compression rotors, higher rpm, trick VDI, electrical OMP, updated ECU, etc., the S5 engine still only made 9.6% more peak horsepower in stock form. The AFM can't possibly make very much of a difference.

I think you made the right decision in spending your time on a standalone EMS rather than writing up an insignificant ghetto mod. Anybody who is seriously concerned about a restriction is going to use a standalone EMS in speed-density or Alpha-N mode rather than bother with antiquated electronics from the 1980's.

 

Thanks alot Gentlemen,..Seriously.
alot of really good Info On and Off the thread.(I looked at Links)
I am not going to beat the horse anymore.I was going to give the FC a "heart transplant"(TII from N/A) this spring.I thought if things could be Done Easily then Fine.So no Getting rid of the S4 AFM..Got it!.

 

Don't base your opinion of that on the power differences between S4's and S5's.
They changed way too many things including tuning to figure out what did what and where.

There are lots of things that people do that have zero benefit to power. Throttlebody porting and gasket matching are two that come to mind. I'm not saying anyone should go out of their way to swap from one afm to another. I wouldn't switch to an S5 afm from an S4. But the S5 afm does flow more. I'd personally rather just get rid of it as I did. However it is a restriction that does cost power and having the ability to switch to a hot wire maf would mean having the ability to switch to a system that isn't a restriction as those just aren't. If a person could do that and then use an r-tek, they could get a really nice system.

I don't regret going to a standalone. I would just like to see the maf conversion info made public as it would be a benefit even if it is a small one for most.

 

yes you can and yes it does work, my friends fc uses a s5 maf on an s4 ecu, works just fine. more importantly i have a better idea altogether. the 93 toyota supra uses the same afm as the s4 on their nonturbo, same part number. but the twin turbo uses a hotmire that has an s5 plug. im fairly certin you could do the same swap using the supra turbo one and bam, no stupid restriction anymore. i just need some one with a supra afm...

 

you could get rid of the AFM all toghether and get a MAP sensor, saw a couple threads about that while looking at my ECU options, I saw someone found a MAP that had a piggyback ecu that makes the stock ecu think its still the flapper... just a thought
i am going standalone myself and a map, if i spend that much on an ecu a couple more bucks on a map is worth the little bit of more air flow, don't want that s/c starving... not that i think it will but why not make things look better as well

 

I think you know that it is not an opinion, and that it has much more basis than what I stated in my post.

A ported throttle body, matched gaskets, and other worthless mods do in fact flow more, but I think we both know that they are still worthless to the average street driver. The S4 vs. S5 AFM debate is yet another worthless venture that you can add to your list.

The hot wire MAF is also a small restriction. The only way to have no restriction is to use a standalone EMS in Alpha-N mode.